Firefighters are searching for people they believe may have been caught inside a house that was left badly damaged in a fire.
Neighbours reported sounds of a loud explosion in the village of Riddings, near Alfreton in Derbyshire early this morning.
Fire crews found the building in Valley View Road "well alight" when they arrived at 7.30am, and most of the roof and loft area of the brick house was destroyed in the incident.
Neighbours have been evacuated and specialists are now trying to make the house safe before firefighters can search the property for survivors.
David Lovett, an incident commander from Derbyshire Fire and Rescue Service, said three crews were sent to the street after reports of a house fire and possible explosion.
He told the BBC: "They initially turned up, the house was well-alight and on fire and there was a partial collapse of the structure.
"At the moment we have dealt with the fire situation and that is under control, we have evacuated a neighbouring property and we are working with some specialists now to try to ensure that the structure is safe so that we can do a full and thorough search of it.
"When we received the initial call there were some suggestion that there may be possibly people inside, so we are treating it as a search at the moment.
"What we are prioritising is getting the structure safe so we can get inside and do a thorough search."
Police and ambulance crews are also at the scene and the street has been cordoned off.
Mark Robins, 32, of nearby Shawcroft Avenue, told the Derby Telegraph he was awoken by the sound of the explosion this morning.
He said: "When you are lying in bed, you don't know what is going on but it sounded like a loud bang, followed by a noise that sounded like rubble going down into a skip.
"The house was in flames, with a lot of rubble everywhere, so I rang the fire brigade."